I'm not sure when it started happening, but my jeep smells like sulfer from time to time. I have no idea what it is, but it is produced by the engine in some way or form. Should i be concerned; what is it?

Funny, haha, but seriously i have no clue what it is and if it is some by rpoduct that i am burning. I've noticed a lot of soot on the tail pipe and my engine runs real bad sometimes (see other related topics). I'm not sure if it's all part of the same problem.

Check the compression in the first cylinder. You may be getting half burned gas-air mix blowing past the rings. Also do you have any evidence of oil in the air filter or airbox? Notice a high pitched wooshing sound? I have a sooty tailpipe (borla no less) and mine smells too. Let me know whatcha got and I'll help you the best I can
Willis

Black 91' YJ with fresh 4.0, Sitting on 31x11.5 Mickey Baja MTX's on 15x10 AR767, Borla Stainless cat-back, free flow cat, it seems like I keep breaking necessary parts just about the time I get enough money together for the fun stuff!!!

This sounds like a job for cat converter cleaner. Go to your local auto parts store and get a can. (About $5.00) Use it in your gas, or pour it down your carb for a faster fix. (read instructions)It will say right on the can "for that rotten egg smell"

It definitely sounds like it is your cat. Although cats are designed typically to outlast the vehicle, they sometimes for fail. I would first try getting a can of cat cleaner, but if that doesn't work, you may be in the market for a new one. That's alright though, because you can find reasonable deals from catalogs like Essentials that sell high-flow cats that will even let your jeep breath better, while still remaining emissions legal.

I just got a new exhaust system , and the problem has persisted. It included a new high flow cat. The battery is fairly new also, but i'll chack that and the compression ratios all the way around. Thnaks for all your help guys.

Originally posted by zuck2001:I just got a new exhaust system , and the problem has persisted. It included a new high flow cat. The battery is fairly new also, but i'll chack that and the compression ratios all the way around. Thnaks for all your help guys.

Does the smell get significantly worse when going up hills or when the engine is working hard?

Mine makes a funny smell too. Not sure what it is but it kinda burns my eyes after driving it for a long distance.

Well thanks guys, I've figured it out. The clutch hasn't been hanged, ever. I noticed the smell and correlated the with the rough shifting and found that y clutch is alomost fried. It's kind of convenient because my tranny is going out too. Time for a NP4500 with an Atlas II and a centerforce 3.